As the digital camera technology advances rapidly in recent years, various electronic devices (such as digital cameras and camcorders, etc) are introduced constantly to the market. Not only the quality becomes increasingly higher, but the volume of products also becomes increasingly less, and their market price becomes lower gradually. These electronic image capturing devices available in the market become popular, and they are installed and applied extensively to different computer devices (such as digital personal assistants and notebook computers) and communications devices (such as mobile phones and video-conferencing phones), so that users can communicate with each other online through computers or communications devices or send real-time images captured by the digital image capturing devices in the online communication process, and a user can know about the facial expressions of the other party from the received real-time images.
In our communications, a facial expression generally plays an important role. The facial expressions not only reflect the attitudes of a person, but also express the feelings of our happiness, anger, sorrow, and joy, and thus the online videoconference communications through computers or communications devices are better than traditional network communications, and naturally attract more attentions of consumers. However, the images captured by digital image capturing device in the videoconference or chatting conducted over existing computers or communications devices also include images other than a face and facial expressions such as the image of the environment where the photographer is located, and the image of the photographer's body. Therefore, if the environment of the photographed person is very private (such as the bedroom) or the clothing (such as underwear) is not suitable to be revealed to the public, then the online videoconferencing or chatting is not appropriate to be held through computers or communications devices. Since the image captured instantly by the digital image capturing device usually involves a larger quantity of data, it requires a broader bandwidth for transmitting the data over the network. The video images cannot be transmitted instantly to the opposite party, and a delay will occur during the videoconference or chatting conducted through a narrower band of network, and both parties cannot have actual feelings and joys of chatting. Therefore, finding a way of transmitting a user's facial expressions for a videoconference or a chatting over the network, such that the opposite party can see the facial expressions without revealing the chatting location or personal privacy becomes a subject for videoconferencing system designers and manufacturers.